Configurations, and parallelograms associated to centers of mass

The purpose of this article is to \begin{enumerate} \item define $M(t,k)$ the $t$-fold center of mass arrangement for $k$ points in the plane, \item give elementary properties of $M(t,k)$ and \item give consequences concerning the space $M(2,k)$ of $k$ distinct points in the plane, no four of which are the vertices of a parallelogram. \end{enumerate} The main result proven in this article is that the classical unordered configuration of $k$ points in the plane is not a retract up to homotopy of the space of $k$ unordered distinct points in the plane, no four of which are the vertices of a parallelogram. The proof below is homotopy theoretic without an explicit computation of the homology of these spaces. In addition, a second, speculative part of this article arises from the failure of these methods in the case of odd primes $p$. This failure gives rise to a candidate for the localization at odd primes $p$ of the double loop space of an odd sphere obtained from the $p$-fold center of mass arrangement. Potential consequences are listed.Comment: 11 page

The conductance of a multi-mode ballistic ring: beyond Landauer and Kubo

The Landauer conductance of a two terminal device equals to the number of open modes in the weak scattering limit. What is the corresponding result if we close the system into a ring? Is it still bounded by the number of open modes? Or is it unbounded as in the semi-classical (Drude) analysis? It turns out that the calculation of the mesoscopic conductance is similar to solving a percolation problem. The "percolation" is in energy space rather than in real space. The non-universal structures and the sparsity of the perturbation matrix cannot be ignored.Comment: 7 pages, 8 figures, with the correct version of Figs.6-

Antecedents and consequences of market orientation in universities: Literature review and conceptual framework

Recent developments in marketing theory have resulted in the conceptualisation of the market orientation construct in different cultural and industrial settings. However, there is little research investigating the applicability of market orientation in the higher education context. Building on the existing literature on market orientation and higher education marketing, the authors propose a theoretical framework of market orientation from a higher education management perspective. The framework analysis leads to propositions relating to the antecedents and consequences of market oriented universities. On the basis of the formulated propositions, the authors conclude with a discussion of the implications both for academia and practice and further research

Development of strategies to improve quality and safety and reduce cost of production in organic and ‘low input‘ crop production systems

The overall aims of organic and low input crop production include the economically viable and environmentally sound production of high quality food and feed. Technological bottlenecks in such systems include insufficient and instable yields and in some instances unsatisfactory processing, sensory and/or nutritional quality of the final product. Recently, concerns have also been raised that the intensive use of manures may lead to increased risk for contamination of food by enteropathogenic micro-organisms. Crop production in low input systems is based on key pillars, i.e. (i) a fertile soil which provides sufficient capacity to allow for plant growth while preventing soil-borne diseases, (ii) high quality, disease-free seeds and plant material, (iii) a crop-specific soil fertility management to provide sufficient nutrients for optimum plant growth, and (iv) adequate crop protection techniques to prevent damage due to noxious organisms. In the QLIF project we develop improved component strategies to overcome technological bottlenecks in annual (wheat, lettuce, tomato) and perennial (apple) crop production systems. In this paper we report the progress achieved so far

Protocyanobacteria: Oxygenic and Anoxygenic photosynthesis in mat-forming bacteria

The oldest record of life is preserved in prePhanerozoic stromatolites dated 3500 million years old and is most likely of filamentous mat-forming cyanobacteria. The sedimentary records of cyanobacterial mats in stromatolites are the most abundant record of life throughout the prePhanerozoic. Stromatolites persisted into the Phanerozoic Eon, yet they become much less pronounced relative to earlier ones. The abundance and persistence of cyanobacterial mats throughout most of geological time point to the evolutionary success of these kinds of microbial communities and their possible role in the evolution of the earth and atmosphere

Social Sector Business Ventures: The Critical Factors That Maximize Success

This paper seeks to help social sector leaders understand the factors that they should consider when launching revenue-generating business ventures. Given that much of the research on social sector business ventures is based on the personal experiences of individual practitioners, there is a wide array of advice for organizational leaders who are thinking about launching business ventures. Consequently, we approach the subject of social sector business ventures in a systematic and analytic way in order to determine what organizational leaders really need to know about launching successful ventures. We introduce a framework called "business in a box" that separates the process of thinking about launching business ventures from the organizational characteristics and dynamics that influence these ventures. We assert that organizational leaders who wish to maximize the success of their business ventures must explore (1) what is "inside" the box (The Business and its Context) to understand the business fundamentals of launching a venture and (2) what is "outside" the box (Assets and Internal Destructive Forces) to understand the forces and dynamics within the organizational context that impact these ventures.This publication is Hauser Center Working Paper No. 43. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

Eulerian Statistically Preserved Structures in Passive Scalar Advection

We analyze numerically the time-dependent linear operators that govern the dynamics of Eulerian correlation functions of a decaying passive scalar advected by a stationary, forced 2-dimensional Navier-Stokes turbulence. We show how to naturally discuss the dynamics in terms of effective compact operators that display Eulerian Statistically Preserved Structures which determine the anomalous scaling of the correlation functions. In passing we point out a bonus of the present approach, in providing analytic predictions for the time-dependent correlation functions in decaying turbulent transport.Comment: 10 pages, 10 figures. Submitted to Phys. Rev.

Second order coupling between excited atoms and surface polaritons

Casimir-Polder interactions between an atom and a macroscopic body are typically regarded as due to the exchange of virtual photons. This is strictly true only at zero temperature. At finite temperature, real-photon exchange can provide a significant contribution to the overall dispersion interaction. Here we describe a new resonant two-photon process between an atom and a planar interface. We derive a second order effective Hamiltonian to explain how atoms can couple resonantly to the surface polariton modes of the dielectric medium. This leads to second-order energy exchanges which we compare with the standard nonresonant Casimir-Polder energy.Comment: 7 pages, 2 figure

Stochastic Cahn-Hilliard equation with double singular nonlinearities and two reflections

We consider a stochastic partial differential equation with two logarithmic nonlinearities, with two reflections at 1 and -1 and with a constraint of conservation of the space average. The equation, driven by the derivative in space of a space-time white noise, contains a bi-Laplacian in the drift. The lack of the maximum principle for the bi-Laplacian generates difficulties for the classical penalization method, which uses a crucial monotonicity property. Being inspired by the works of Debussche, Gouden\`ege and Zambotti, we obtain existence and uniqueness of solution for initial conditions in the interval $(-1,1)$. Finally, we prove that the unique invariant measure is ergodic, and we give a result of exponential mixing